>In the 10 frame deep brood box, do the bees always keep honey and pollen frames in the outside frame positions? If so, is this always the case.
They are bees. Nothing is "always the case". Usually yes.
> Meaning, in for example: in the first or second chamber, would it ever be 10 frames of brood only, with no reserves stored in there.
Possibly, yes. But there is usually some around the top and the sides of each frame anyway.
>It is confusing to me. What is the "average" number of frames in the brood nest of one box?
There is none. Sometimes a queen lays up about three frames in each of five boxes. Sometimes she lays all the way across one box.
>I think where the confusion is also coming from is that I wrote on the forum that I had many, many extra frames of pollen and pollen/honey frames left over from last year, being preserved in the freezer. It was indicated to put the pollen frame beside the brood nest. How many frames have to be left open for the brood nest?
For every frame of brood they rear they will burn up one frame of that pollen. It will quickly be open for use as brood.